FRIDAY, July 29, 2016 (HealthDay News) -- People dealing with the itchy skin condition known as eczema may have other medical conditions to cope with as well, including heart disease, a dermatologist says.

Eczema, which causes dry, red patches of skin and intense itchiness, affects an estimated one-quarter of children in the United States. And, as many as seven million adults also have eczema, Dr. Jonathan Silverberg said in an American Academy of Dermatology news release.

"Although it affects the skin, eczema is not just skin-deep. This disease can have a serious impact on patients' quality of life and overall health, both physically and mentally," Silverberg said.

He's assistant professor in dermatology, medical social sciences and preventive medicine at Northwestern University Feinberg School of Medicine in Chicago.

Eczema has been linked to an increased risk of health conditions such as asthma, hay fever, food allergy, obesity and heart disease, Silverberg said.

The reasons for this are unclear. But, the connection may be eczema-related inflammation affecting the entire body, he said. Or, the negative effects of eczema symptoms on sleep and health habits may play a role, he added.

People with eczema also have a higher risk of skin and other infections. And, the frequent intense itching of eczema and its effect on the skin's appearance may contribute to a greater risk of mental health disorders, such as anxiety and depression, Silverberg said.

Controlling flare-ups of eczema symptoms may help reduce the risk of problems such as sleep disturbance, but heart disease and other conditions may develop due to eczema's long-term effects on the body, Silverberg said.

That's why it's important for treatment to not only improve symptoms in the short-term, but also to manage eczema for the long-term, he said.